Britain's FTSE buoyed by StanChart and Sainsbury

* FTSE 100 stays close to 3-month lows

* Weir falls after warning of some tough market conditions

* Sainsbury rebounds despite another drop in sales

By Sudip Kar-Gupta

LONDON, June 10 (Reuters) - Britain's top equity index edged up from three-month lows on Wednesday, propped up by advances in banking group Standard Chartered (HKSE: 2888.HK - news) and supermarket group Sainsbury.

The blue-chip FTSE 100 index rose 0.1 percent to 6,760.35 points, close to its lowest level reached since late March and 5 percent below a record high of 7,122.74 points hit in April.

European equity markets have fallen back from the year's previous peaks over the last month, due partly to bond market jitters and concerns over Greece's debt situation.

The FTSE 100 is up around 3 percent since the start of 2015, underperforming the pan-European FTSEurofirst 300 index , which is up 11 percent.

"I can see some more downside going into the end of the week, but if we do get a resolution on Greece, we'll look to buy into the market," said Thames Capital Markets' chief strategist Nav Banwait.

Standard Chartered rose 2.2 percent.

Traders said one reason for the rise in StanChart's shares was the possibility that British Finance Minister George Osborne might change a bank levy on the British banking industry at a speech later on Wednesday.

Any move to re-focus the levy back onto the UK balance sheets of global banks would benefit Standard Chartered, as the vast majority of Standard Chartered's business is conducted outside of Britain, traders said.

Supermarket operator Sainsbury also rose 1.6 percent.

Even though Sainsbury reported a sixth straight quarter of declining underlying sales, some analysts said the company had performed ahead of market expectations.

Sainsbury's rise also dragged up the shares of rivals such as Tesco (Xetra: 852647 - news) and Morrison.

Engineer Weir Group was the worst-performing FTSE 100 stock in percentage terms, dropping 2.9 percent after warning of tough conditions for its unit dealing with the oil and gas sector.

(Additional reporting by Tricia Wright; Editing by Raissa Kasolowsky)