UK's SIG rises as co expects narrower like-for-like sales decline in March, April
** Shares of British building materials supplier SIG SHI.L up 5% at 8.08 pence ** Co says trading started to improve from March; expects like-for-like sales decline of 2%-3% over March and April vs 5% fall in Q1 ** SHI says Q1 cash flow ahead of plan, group continues to expect to maintain healthy liquidity throughout year ** Despite gains, SHI down about 23% YTD (Reporting by Megha Anilkumar Nair) ((MeghaAnilkumar.Nair@thomsonreuters.com;))