Sept 8 (Reuters) - Canadian oil and gas producer

Strathcona Resources ( STHRF ) raised its all-share offer for MEG

Energy ( MEGEF ) on Monday, seeking to outbid Cenovus Energy ( CVE )

.

Strathcona said its revised offer values MEG at C$30.86 per

share, compared with Cenovus' valuation of C$27.79 in the

cash-and-stock agreement announced in August.

Strathcona, backed by private equity firm Waterous Energy

Fund, has spent recent weeks boosting its stake in MEG.

As of last week, it owns or controls about 14.2% of MEG's

outstanding shares, strengthening its position as a significant

minority investor.

($1 = 1.3815 Canadian dollars)