Mr Gowda is expected to put down his letter on Saturday, Jul 7. Yeddyurappa's loyalist Jagadish Shettar will become the successor of Gowda, sources added.
Sadananda Gowda on Saturday headed towards New Delhi and sources informed that BJP will make its official announcement only after Gowda meets Nitin Gadkari and LK Advani.
Before leaving for the national capital, Gowda pleaded with the party that it should not take any decision in "haste". Gowda also asserted that he has strived to give a corruption-free administration in the last 11 months after he was appointed as Chief Minister.
Gowda took over from Yeddyurappa in Aug 2011 following the decision of BJP high command to axe him in the wake of allegations of corruption against him.
Yeddyurappa, who projected Gowda as his successor then, has been demanding his ouster now and wants to install Rural Development Minister Jagadish Shettar as the CM of the state.
Earlier, Shettar, also a Lingayat, was supported earlier by Ananth Kumar and was rejected by Yeddyurappa. Ananth Kumar was an arch rival of Yeddyurappa. However, political game in the state has taken so many surprising turns and Yeddyurappa forced BJP high command to sack Gowda from the CM post.