The letter was written on October 4, but released today.
Patel's letter to Shah comes at a time when the BJP is in the process of forming three-member panels for each of the Assembly constituencies in the state to select the party candidates for the Assembly polls due later this year.
There has been a demand from a section of the BJP to declare the veteran politician as the party's chief ministerial face in Gujarat, which is witnessing a quota agitation by the Patel community.
A tweet by BJP leader Subramanian Swamy, asking the party to make Patel the chief ministerial face in Gujarat had led to speculation about the former chief minister once again vying for the top post.
Patel, however, cited her age as the reason for not contesting the polls.
"When I had resigned as the chief minister of Gujarat, I had done it in accordance with the party rule that nobody beyond the age of 75 should hold (any) post. Today also, under the same rule, I would like to say that I do not want to contest the upcoming Assembly polls," she wrote to Shah.
Patel also told the party chief that she was ready to perform whatever duty the party gave her as regards the upcoming election.
In the letter, she expressed gratitude to the party for making her the first woman chief minister of Gujarat.
Patel, who is considered close to Prime Minister Narendra Modi, was made the chief minister of Gujarat after the latter shifted to New Delhi in May, 2014.
However, her handling of the Patidar quota agitation and the episode of Dalit atrocities in Una did not go down well with the top BJP leadership.
Patel resigned from her post in August, 2016 and was replaced by Vijay Rupani.
When contacted, state BJP spokesperson Bharat Pandya said it was for the party leadership to take a decision on Patel's request.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)