* Main share index up slightly

* Shilling quickly reverses gains during session

(Adds shilling closing rate, stocks, bonds)

By George Obulutsa

NAIROBI, Sept 8 (Reuters) - Commercial banks quoted the Kenyan shilling KES= at 88.60/70 to the dollar at 1300 GMT on Monday, the same as Friday's close, after it gained briefly during the session before reversing those gains, while stocks closed slightly higher.

Traders said they expected the shilling to trade in the 88.50 to 89.00 range in coming days and have a bias towards strengthening.

During the session it touched 88.30/40 to the dollar before reversing the gains.

Traders said the central bank mopped up 5.93 billion shillings earlier in the session, but this had little impact on the local currency. It had sought to mop up 8 billion shillings.

"I still think (dollar) supply is the issue," Julius Kiriinya, trader at African Banking Corporation, said.

Traders said the shilling's weakening had also been limited by slowing dollar demand.

Sheikh Mehran, head of trading at I&M Bank, said there was also an increase in central bank reserves. "So generally, the shilling might strengthen a bit," he added.

The central bank said in its latest weekly bulletin that official usable foreign exchange reserves rose to $6.377 billion in the week ending Sept. 4 from $6.257 billion a week before.

On the Nairobi Securities Exchange, the main NSE-20 Share Index .NSE20 was up by 8.48 points, or 0.2 percent, to close at 5,168.80 points.

On the secondary market, government bonds worth a total 1.38 billion shillings were traded compared with 1.6 billion shillings on Friday.

KES= KES1= ...........................Shilling spot rates KESF= 0#KESF= .....................Shilling forward rates EURKES= KESX= KESX1= .......................Cross rates KES=KE ..................................Local contributors CBKINDEX .......................Central Bank of Kenya Index KE/DEBT .....................Kenyan Bonds contributor pages CBK03 CBK06 KE3MTB= ...............Treasury bill yields CBK04 ..................Central bank open market operations CBK07 .........................Horizontal repo transactions KEIBR= , CBK02 ................Daily interbank lending rate 0#KETSYSTR= .............................Kenya Bond pricing ECONAFRICA ..................Real time Africa economic data ...........................African economic news .NSE20 .................................NSE-20 Share Index .NASI .................................NSE All Share Index .FTFNKEN1 ...........................FT NSE Kenya 15 Index .FTFNKEN2 .......................... FT NSE Kenya 25 Index SPEED GUIDES: REUTERS KES/1 KE/DEBT MONEY KE/EQUITY

(Reporting by George Obulutsa; Editing by Janet Lawrence) ((george.obulutsa@thomsonreuters.com; Tel: +254 20 499 1232; Reuters Messaging: george.obulutsa.thomsonreuters.com@reuters.net))

Keywords: KENYA MARKETS/